Why saint and Sages of Hinduism eat dinner before the sunset ?

You must have known about Yogis, Saints and Sages. But very few peoples know that Saint and Sadhus complete their dinner before sunset. You must be thinking that why they do like this. Is there any scientific reason behind this?. Ya, there is many scientific proof to explain it. The reason behind this is darkness. In ancient time, there was no electric city, and not having sufficient source for lighting. Hence people used to complete their major part of work before sunset and sleep early. Not only dinner, there is other works also, which were not allowed to perform at night. In puranas and upanishads, major and critical works are refused to do at night like cooking, eating,  shaving, cutting nails, running, climbing on tree, collecting flower from tree and collecting wood.
    Cooking of food was also not allowed at night because during cooking, there was possibilty that night creatures or insects may fall in cooked food and it may cause unhealthy for human being. For same reason, eating food at night was not allowed due to improper visibility. Cutting nail was not allowed at night because during cutting of nail, one may harm himself by cutter.
     Collecting flower from tree is dangerous because of improper visibility and presence of poisonous snake or insect on branches of flowering plant may bite any one.  
          One more reason is there for completing dinner before sunset. As per Ayurveda principal. There should be two hour gap between dinner and bed time. Many peoples suffers from constipation, gas, acidity and indigestion because of peoples complete their dinner and soon they go to bed. Due to this, peoples also suffers from overweight and  obesity. But in modern age, everywhere electricity is available. So we can eat at night but should have maximum 2 hour gap between dinner and sleep. Also western peoples accept that after taking dinner one must walk for some distance better digestion. Thank You